COMMENTARY Carotid Artery Angioplasty and Stenting Without Distal Embolic Protection Devices Paul M. Foreman, MD Mark R. Harrigan, MD Department of Neurosurgery, University of Alabama, Birmingham, Alabama Correspondence: Mark R. Harrigan, MD, Faculty Ofce Tower 1005, 1720 2nd Ave. S., Birmingham, Alabama 35294. E-mail: mharrigan@uabmc.edu Received, July 31, 2016. Accepted, October 19, 2016. Published Online, December 7, 2016. Copyright C  2016 by the Congress of Neurological Surgeons I t seems to make sense, on an intuitive level, that maneuvers to prevent debris from traveling to the brain during carotid stenting are worthwhile. Every experienced neurointer- ventionalist has observed debris in filter devices. Indeed, visible debris has been reported in some 15% of cases, 1 and microscopic debris has been reported in 100% of cases. 2 The use of embolic protection techniques during carotid angioplasty and stenting is currently a standard of care. Embolic protection is so widely accepted at the present time that it is required for reimbursement of carotid stenting by Medicare. 3 However, current embolic protection technology is imperfect. Filter devices must be navigated through the region of stenosis prior to deployment, which may cause release of debris from the atherosclerotic plaque. Filter devices are also vulnerable to malpositioning, and, even when well positioned in favorable anatomy, cannot protect against particles smaller than the micropores in the filter. A small but growing literature suggests that commonly used embolic protection strategies are not as protective against ischemic stroke during carotid stenting as previously thought. 4, 5 Challenges to the prevailing wisdom are always welcome, provided that they are thoughtful and carefully done. Given the contemporary level of acceptance of embolic protection, any routine carotid stenting done without embolic protection should be done only with Institutional Review Board’s approval and patient consent. Rather than a sober and careful investigation of the role of embolic protection in carotid stenting, the present study is a retrospective chart review of 166 cases in which the authors did not use distal protection devices. The authors’ claim that no patient had a neurological complication is not credible for several reasons. First, the results do not seem plausible. One is hard pressed to find any published carotid stent study with more than a handful of cases that reported zero neurological complications. The authors’ claims are not made any more believable by the absence of independent neurological assessment or follow- up brain imaging. Second, other aspects of the management of the patients in this study are also outside the mainstream, which further dilutes the credibility of the findings. Routine use of general anesthesia, electroencephalographic monitoring, and treatment of asymptomatic restenosis are not conventional for carotid stenting. For the results of any clinical study to be generalizable, clinical management should be as close to convention as possible, except for the clinical factor being studied. Should all carotid stenters begin doing these procedures without distal protection, under general anesthesia, with electroencephalography, in hopes that the risk of neurological complications will vanish? Probably not. The medical literature is already saturated with questionable retrospective studies; sadly, this manuscript is only another example. Disclosure The authors have no personal, financial, or institutional interest in any of the drugs, materials, or devices described in this article. REFERENCES 1. Giannakopoulos TG, Moulakakis K, Sfyroeras GS, et al. Association between plaque echogenicity and embolic material captured in filter during protected carotid angio- plasty and stenting. Eur J Vasc Endovasc Surg. 2012;43(6): 627-631. 2. Yang M, Yu Y, Walsh WR, et al. A microscopic and biomarker evaluation of embolic filter debris collected during carotid artery stenting. J Endovasc Ther. 2016;23(2):275-284. 3. Centers for Medicare and Medicaid Services. Decision Memo for Carotid Artery Stenting (CAG-00085R). Available at: https://www.cms.gov/medicare-coverage-database/details/ nca-decision-memo.aspx?NCAId=157&ver=29&NcaName =Carotid+Artery+Stenting+(1st+Recon). Accessed July 24, 2016. 4. Khan M, Qureshi AI. Factors associated with increased rates of post-procedural stroke or death following carotid artery stent placement: a systematic review. J Vasc Interv Neurol. 2014;7(1):11-20. 5. Macdonald S, Evans DH, Griffiths PD, et al. Filter-protected versus unprotected carotid artery stenting: a randomised trial. Cerebrovasc Dis. 2010;29(3):282-289. 66 | VOLUME 80 | NUMBER 1 | JANUARY 2017 www.neurosurgery-online.com Downloaded from https://academic.oup.com/neurosurgery/article-abstract/80/1/66/2645438 by guest on 28 May 2020